People feel better if they think that they live in a ‘just’ society and philosophers, such as John Rawls, have tried to propound “principles of justice” for legitimising governance. He assumed that “free and rational persons” would, by the use of reason, be able to agree upon a set of “principles of justice” which would then constitute a foundation for deciding how to govern – but justice is a contested word.
Justice, in Rawls’s narrative, would be guaranteed by an “original agreement”. There are at least three reasons why such an approach would not guarantee agreement on governance in a real society:
- Any process of reasoning begins from a starting point – a set of facts, assumptions, perspectives, and logical premises – and these starting points can be very different: as illustrated by the above example of collectivists and individualists, who might both describe themselves as “free and rational persons”. There are also societies which prioritise family and tribal loyalty, or duty to God, to name two further alternative starting points. These different foundations lead to different philosophies, which may be internally self-consistent and which are defended by their adherents as being valid. People’s inherent diversity ensures that there will never be a single set of universally accepted “principles of justice”.
- In a real society, people will make different interpretations of the circumstances in which governance responses are required. For example, the measures taken in Britain to prepare for the Second World War profoundly affected many people’s lives, but there was disagreement about whether the preparations were necessary: some people, including Prime Minister Neville Chamberlain, thought that appeasement would avoid a war.
- Real people don’t always use principled reasoning when making their choices about how they want to be governed. Other factors, such as the personalities of leadership candidates or a desire for change, may be more potent than the different political philosophies on offer in a democratic election for example. It should not be assumed that reason is the best way of determining what would be best for people who have emotions and who are influenced by their history.
For these reasons, it is highly unlikely that trying to reach agreement on philosophical “principles of justice” would be a practical way of making governance acceptable to people in real situations. Although Rawls updated his work in later books, to reflect some of the problems inherent in reaching an agreement in a pluralist society, he was still seeking a universal and timeless solution and his privileging of “reason” failed to give sufficient recognition to people’s inherent diversity. In this book, in agreement with Amartya Sen, it is assumed that perfection is not attainable in the short term, if ever, but that this need not prevent people’s lives from being improved by societies making “social choices”.
 John Rawls defined his approach in A Theory of Justice, Section 3, p. 10 (PDF p.34):
“…the guiding idea is that the principles of justice for the basic structure of society are the object of the original agreement. They are the principles that free and rational persons concerned to further their own interests would accept in an initial position of equality as defining the fundamental terms of the association. These principles are to regulate all further agreements; they specify the kinds of social cooperation that can be entered into and the forms of government that can be established. This way of regarding the principles of justice I shall call justice as fairness.”
A PDF copy of the book was available in February 2018 at http://www.consiglio.regione.campania.it/cms/CM_PORTALE_CRC/servlet/Docs?dir=docs_biblio&file=BiblioContenuto_3641.pdf.
 John Rawls’s later books include Political Liberalism and The Law of Peoples.
 Rawls, in Political Liberalism, bases his argument upon the supremacy of reason as a justifying principle in governance, and upon the implication that people with diverse views would be able to reach meaningful agreements by exercising reason:
“our exercise of political power is proper and hence justifiable only when it is exercised in accordance with a constitution the essentials of which all citizens may reasonably be expected to endorse in the light of principles and ideals acceptable to them as reasonable and rational. This is the liberal principle of legitimacy.” (p. 217)
Daniel Bell’s Communitarianism entry in The Stanford Encyclopedia of Philosophy (Spring 2012 Edition), Edward N. Zalta (ed.), outlines some challenges to Rawls. These include Michael Walzer, whose book Spheres of Justice is quoted as arguing that “effective social criticism must derive from and resonate with the habits and traditions of actual people living in specific times and places”. The same entry references several other writers and their works as being critical of Rawls’s approach; it was available in February 2018 at http://plato.stanford.edu/archives/spr2012/entries/communitarianism/.
 Amartya Sen’s interpretation of social choice theory is in chapter 4 of The Idea of Justice.